Nanomechanical Characterization of Amyloid Fibrils Using Single-Molecule Experiments and Computational Simulations

Figure 2

Nanomechanical properties of multistranded amyloid fibrils. (a) Schematic illustration of measuring the angle between two tangent vectors to extract the mechanical properties of the fibril using polymer chain statistics. (b) The ensemble averages of correlation functions (defined as cosine values of angles) for a multistranded fibril made of single (blue), two (red), and three (yellow) filaments, respectively, are measured from AFM experiments. The measured experimental results (indicated by blue, red, and yellow dots) are well fitted to theoretical predictions from polymer chain statistics (indicated by blue, red, and yellow lines). (c) Persistent length and helical pitch for amyloid fibrils composed of single, two, and three filaments, respectively. (d) The distribution of the difference between maximum and minimum AFM heights (thicknesses) of amyloid fibrils. (e) AFM images (shown in lower panel) and corresponding coarse-grained models (shown in upper panel) provide the left-handed multistranded amyloid fibrils made of one to five filaments, respectively. Figures are adopted with permission from [16].

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